Rigid airship



v May 13, 1930.

c. D. BURNEY ET AL 1,758,143

RIGID AIRSHIP Filed Aug. 20, 1927 3 Sheets-Sheet l y 13, 1930. v c. D.BURNUEY ET AL 1,758,143

RIGID AIRS-HIP Filed Aug. 20, 1927 3 Sheets-Sheet 2 May 13, 1930.

c. D. BURNEY ET AL 1,758,143

RIGID AIRSHIP Filed Aug. 20, 1927 3 Sheets-Sheet 3 Patented May 13, 1930UNITED STATES PATENT CHARLES DENNISTON EBUBNEY, BARNES ILLE WALLIS, ANDJOHN EDWIN PLE, WESTMINSTER, LONDON, ENGLAND, ASSIGNOBS TO AIRSI-IIPGUARAN'IEEE COMPANY, LIMITED, OF WESTMINSTER, ENGLAND, BRITISH COMPANYRIGID Amsrnr Application filed August 20, 1927, serial No. 214,328, andin Great Britain September 17,1926.

This invention relates to rigid airships. In rigid airships the mainstructureof the hull usually consists of longitudinal girders andtransverse frame members, the latter be= ing usually in the form ofpolygonal rings.

frame or ring members are constituted by relatively shallow girders, forexample by girders the depth of which is of the order of approximately2% orunder ofthe diameter of the frame, it isessential that the frameshall be provided with a system of bulkhead wiring which will not onlybe adequate to restrain deflection of the ring members under the loadimposed upon them during nor-' mal flight when both the gas bags locatedon contiguous sides of the bulkhead wiring are fully inflated, but whichwill also be of such a strength or character that, if one of the gasbags becomes deflated, the tension set up in the bulkhead wiring, due tothe end pressure of the contiguous inflated gas bag or bags as it orthey protrude or tend to protrude laterally into the space formerlyoccupied by the deflated bags, will not throw too great acomprcssioninto the transverseframe members.

It has heretofore-been impossible to comply with both these conditionsin a satisfactory manner, for, if the bracing wires are put in eitherhand taut or with initial'ten- 40' sion in order to brace a light andshallow transverse frame under normal conditions, then, under abnormalconditions, and when a gas bag is deflated the end pressure of thecontiguous inflatedbag or bags on the bulkas head wiring sets upaihighdegree of compression in the frame members which might causefailure or deformation 1n a light or narrow frame and therefore incertain cases might impose secondary forces and/0r bendingmoments intheilongitudinal girders. On

the other hand if the frames are madesuifie ciently strong orsufficiently. deep to resist deformation or any stresses set up in thedefiated bag condition the additional Weightof such frames, to providefor a circumstance which is actually of abnormal .or unlikelyoccurrence, is objec'tionableto a high degree in a structure where themaximum degree of lightness consistent with strength is.the'desideratum; o

According to one feature of the present invention the wires constitutingthe bulkhead wiring of each transverse frameare so Y'ar ranged that theyradiate outwards in all die rections and at-asuitable distance apartfrom a point located at .or about the axis of the ship, but the outerends of the fwires or certtam of the wires, are'connecte'd'toca-tenaries the ends-of whicha're in turn attached to the I transverseframe members at ;thepoint where they are intersected by thelongitudinal girders.

The; adoption of this arrangement ensures an even distribution of thelateral loading in the bulkhead wiring to all members of the transverse'frame, especially in cases where, as-des'cribed in co-pendingapplication Serial No. 2l4 036, filedArugust 19,1927 a connec tion ismade,'from-the point wherezeach cate nary joins the frame members, tothe 'eir-.

cumferential mesh Wiring surrounding each gas bag. This system isemployed in coin= bination with an axial restraint, thatis to say thecentres of the radially arranged bulkhead wires are interconnected by astranded wire or cable running axially of the ship,,or

connected i012} centrally arranged and rigid girder runningaxially ofthexship' as herein:- a-fter moreparticularly described.

In the foregoing arrangementall the radiallyarranged wires in each panele. the wires connected to the same catenary) are hand taut (i. e. havean initial tension :of approximately 50' to 100 lbs.) in order to bracethe frame under normal conditio-ns'zand to transmit to the framework ina more satisfactory manner than heretofore the lateral loading of thebulkhead wiring under-ab normal or deflatedlbag conditions. According,however, to a further feature of the present invention and to apreferred arrangement only the radially arranged end wires of each panelhave initial tension or are hand taut and, disposed between the tautwires of each panel, is a catenary to which a number. of radiallyarranged and initially slack wires are attached, each catenary extendingbetween a polygonal side of the transverse frame and having each of itsends attached to 'the frame at the points where it is intersected by alongitudinal girder. The taut wires are attached to theframe members atthe same point and/0r contiguous to the slack wires According to anotherfeature of the pres ent invention an axial restraint is provided at orabout the centre of thebulkhead wiring. The axial restraint may beconstituted by a stranded wire cable running axially of the ship throughthe gas bags and having its ends secured to the framework at the noseand tail of the ship. The use of a cable, however, is open to certaindisadvantages in that it extends under the influence of the lateralloading onthe bulkhead wiring, so that it is diificult to determinewhether or not the centre'of theradial wiring is restrained in the planeof the transverse frame. Furthermore, the cable has to be located inposition. when the gas bags are partially inflated, and, apart from thefact thatleakage of the lifting gas occurs, or is liable to occur, atthe openings through which the cable enters and leaves the gas bags, theattachment of the cable in position is very troublesome. Instead of acable, therefore, it is preferred to provide an axial restraintconstituted by a rigid girder which is preferably constructed insections and which has its'ends restrained at the nose or tail of theship in such a manner as to transmit the loads which may occur in theaxial girder into the longitudinal girders of the hull. In order toaccommodate the rigid girder a central opening or core is providedthrough the axis of each gas bag, the openings being prefer v ablylinedwith heavier material than that of which the bag itself iscomposed. The axial girder may be of space frame construction and oftriangular cross section and be built up from sections which arejoinedtogether in a detachable manner at points in or about the plane of thebulkhead wiring.

In order that the said invention may be clearly understood and readilycarried into effect the same will now be described more fully withreference to the accompanying drawing, in which Figure 1 is across-section of an airship fitted with a system of tight and slackbulkhead wiring constructed according to the present invention, as alsowith an axial restraintconstituted by a built-up space frame girder,part only of the slack wiring as also the covering network being shown.

Figure 2 is a typical section showing the a bulge of the gas bag betweenthe taut radialwires when the adjoining gas bag is in deflatedcondition.

Figure 3 is a view on anenlarged scale showing a panel constituted by acatenary, a pair of tight wires and a number of slack wires. 7 y

Figure 4 is a sectional view showing diagrammatically on an enlargedscale the relative bulge at'half radius of the tightand slack wires of apanel when in deflated bag condition.

Figure'5 is a detail view-showing one method which may be adopted forconnecting the ends'ofthe catenaries, as also the tight wire totheframework of the airship.

Figure 6 is a detail view showing one method that may be adopted forconnecting the inner ends of the tight and slack wires to a hub locatedat the axis'of the ship.

v Figure 7 is acorresponding view to Figure 6,showing in greater detailthe construction of the said hub.

Figure 8 is a diagrammatic view of an airship constructed according tothe present invention showing the axial girder which extends lengthwiseof the ship, and v Figure 9 is a detail view showing on a larger scalethe hub at the axis of the ship to which the ends of the taut andslack-radial wires are attached, as also a portion of a spider which ismounted on the said hub and by means of which the axial girder issecured in position. 7 I a A, A are the transverse frame members and B,B the longitudinal girders, C is the axial girder which restrains thegas bags in the plane ofthe transverse frame A, D, D are the hubs at theaxis of the ship and E, E are the spiders for coupling together theparts of the girder G constituting the axial restraint, F,'F are thetight wires of the bulkhead wiring and G, G are the slack wires.

H, H are the slack catenary wires for attaching the slack wires of thebulkhead wiring to the transverse frame members. I is a cord nettingcovering the corner gaps between the catenaries of .the'circumferentialmesh wiring which surrounds the gas bags and the bulkhead wiringcatenaries. J is a cord netting interlaced between the taut and slackwires, F, F and G, G to prevent undue bulging of the gas bag through thesaid wires; K (Figure 2) is an inflated gas bag andK is a deflated gasbag, the gas bags throughout the ship being provided with an axial trunkK to accommodate the axial girder C. In the example shown at Figure 1the airship is provided with a corridor L extending lengthwise of theship and the slack wires G in the panel above the same are of shorterlength than those of other panels;

A suitable mode of attaching'the catenaries mes es H, H and the tautwires-I F consists in bringing the-end of a taut 'wlre F and each end ofa pairof 'contiguous-catenaries H, H within a socket piece H andlocating the latter within, or attaching it to the transverse frame A,turnbuckles H H? being pro vided towards the ends of the catenary wiresand the taut wires to effect the necessary adjustments. By means of thispreferred arrangement there is provided a primarysystemof'radiallyarranged-and hand taut wires F, F which is adequate tobrace or restrain deflections of the relatively light transverse framesA, A under, normal conditions butnot adequate to cope with abnormalordeflated gas bag conditions, and a secondary-system of slack radialwires G, G 'disposed between the taut wires F, F which normally hang.

more or less loosely and only come intoaction duringabnormal or deflatedgas bag conditions, and which, by virtue of theirinitial slackness, arefree to curve or bulge outwardly beyond the plane of the tight wiresunder deflated bag'conditions, so that, for an equal lateral loadingthey sufler less tension than the tightwires.

In theevent of a bag becoming "deflated both the tight and the-slackwires are bulged outwardly as shown at Figures 2 and 4 by the endpressure of the contiguous "inflated gas bag. K beyond'the plane of thetransverse frame A, but the slack wiresG, G as a whole bulge beyond thetight wires while the gas bag itself protrudes through .and beyond thespaces betweenall the radial wires,'thuscausing theprotruding inflatedgas bag to assume a fluted or "cantaloupe-like configuration As the endsofthe catenary to which-the slack wires G, G are attached are notanchored to the taut wires F, F but independentlyattachedtothetransverse frame A their radial tension is separatelytransferred to the frame at each-corner of .the'polygon, and not to orthrough thetaut-bracing wires *F, F.

; Owing to this arrangement the total radial loading in the bulkheadwires in deflated gas bag conditions which istransferred as acompressional force to the transverse frame members fromtheconnections'at each polygonal anglethereof is lessthan wouldbe the caseif'all the wires of the bulkhead wiring were initially taut in-normalbag conditions, as has invariably been thecase in allpreviousproposalsto use a relatively narrow 'or shallow frame. The cordnetis-prefer-ably provided to restrain undue bulgingof thegas bag inthespaces between the SYStGIIl-Ofilfidially arranged wires and this cordnetwork covers both the'taut andthe-slackwires, If desired, and in caseswhere the point of connection of the taut wires and-the ends ofithecatenaries does not pass through the centroid of either or both thetransverse frame members and the intersecting longitudinal girders I aconnection may be made from the said point of attachment to thecircumferential mesh wiring by means of a strop or otherwise asdescribed in our co-pending application Serial No. 214,036, filed August1 9, 1927. The longitudinal girders and the transverse frame members mayalso be so arranged that they intersect one another in such a mannerthattheir centroids are coincident and the lift and shear wiresmay beattached at or approximately at the said coincident centnoids, asuitable method of obtaining this result being described in ourco-pendingpatent application Serial No. 21i,028, 'filedAugust 19,1921. 1

I In view ofthe fact that the resultant normal pressure on the bulkheadwiring is greater at the top than at the :bottom of the bag, it ishighly desirable, in order to prevent the occurrence of unequal stressesor bending moments in the framework, that the inward radial loading dueto endwise pressure on the'bulkhead wiring in deflated bag conditionsshould beequal at eachcorner of the polygon. To this end thedegree ofslackness initially imparted to the slack wires of each successive panelcan be made progressi-vely greater from a minimum at the bottom of theairship to .a maximum at the top thereof. i i

This result can readily be obtained by Joeating theycatenaries H, H inplace and thereafter, by means of the aforesaid turnbuckleslFP, Hlocated between the ends of the catenaries and'their connections to thetransverse frame, slackening out or otherwise adjusting them to thepredetermined extent; Attheir inner ends the :taut andithe slack wiresare attached to the hub 51) as shown more clearly at 'Figuresfi and 9.and'if desired turnbuckles may also be provided foradjusting the endsofthe taut-wires.

A suitable method-of detachably connectingzthe"various sections of thegirder to one another in cases --'.where the girder is of :triangularspace frame construction, constituted, as in the example illustrated,.-by fthree tubular members connected together "by bracing members, isshown more clearly ,at'

Figure 9 where a member .E (which is termed a spider) is providedihavingthree radial arms e (oneacomplete armonly'being shown eachlarmlbeingprovided at its outer extremity with a socket '6 which accommodatesa'connecting piece having screw-+threaded; ends to which the endunembersofithe triangular space frame girder .on contiguous sides thereof areattached by removable coupling rings. iProjecting laterally.of thespider and attached thereto :at the centre thereof in: any suitablemannenmay'be a; stub shaft e onwhich a pair of plates, constituting partof the hubjlD are mounted, the plates being spaced apart by angularlydisplaceable fittings to which the ends of'thetautiand slack wires ofthe bulkhead wiringraresecured. The said stub-shaft 6 may also beprovided with bollard pieces to support the ends of cables 0! from whichthe fuel tanks, ballast, etc., may be suspended.

In locating the axial girder C in position a gas bag is suitablyarranged around each section of the girder and bound in place.Thereafter the sections are hoistedinto place and coupled together bythe coupling pieces carried on the spiders E, the binding for the gasbags is then removed and they are allowed to hang from the axial girderC. The provision of an axial girderhas the advantage that each gas bagissupported at half its height during the filling'operation instead oflying on the bottom of the airship,

and, especially in the larger sizes of airships where the gas bags areof great capacity, this arrangement is advantageous in that it allowsthe supported bags to fill out in a position where damage to the bag isunlikely to occur. Moreover, in deflated bag condition the bag issupported on the girder section at the axis of the ship where it may bepossible to effect a repair without removing both the girder section andthe damaged bag from the ship. As, in deflated gas bagcondition, thegirder section in the bay containing the damaged bag will be incompression and the remaining girder sections of each side thereof intension, means may be provided for retracting the portions of the girderon each side of the section containing the damaged gas bag to relievethe said-section from compression and enable it to be removed.

The provision of an axial restraint constituted by a rigid sectionalgirder fixes definitely the centres of the bulkhead wiring in the planeof each transverse frame. If desired, the space frame girderconstituting the axial restraint may be used for leading controls, etc.,along theship, orf enlarged so as to form an access passage extendingfrom the bow to the stern of the ship. 7

What we claim and desire to secure by Letters Patent of the UnitedStates is 1. A rigid airship'in which the wires constituting thebulkhead wiring radiate outwards in all directions, and at a suitabledistance apart, from a point located at or about the axis of the ship,the outer ends of the wires, or certain of them, being connected tocatenaries, the ends of said catenaries being attached to the frameworkof the airship at the points where the transverse frame members areintersected by the longitudinal glrders.

2. A rigid airship in which the bulkhead wiring comprises a number ofinitially taut wires and a number of'initially slack wires all radiatingfrom a common point in proximity to the axis of the ship.

3. A rigid airship in which the bulkhead wiring comprises a number ofinitially taut wires and a'number of initially slack wires all radiatingfrom a common point in proximity to the axis of the ship and the innerends of the slack wires are attached to a point at or about the axis ofthe ship and the outer ends are connected to catenaries, the taut wiresbeing also radially arranged with their inner ends'attached to a pointat or about the axisof the ship; the ends of said catenaries as also'theouter ends of the taut wires being connected to the framework of theairship at the points where the transverse frame members areintersectedby the longitudinal girders.

4. A rigid airship as claimed in claim 3, in which the contiguous endsof a pair 'of catenaries as also the end of a taut wire are broughtwithin a socket piece which is located within or attached to thetransverse frame.

5. A rigid airship as claimed in claim 3, in which turnbuckles or othertautening devices are provided to enable any necessary adjustment of thetaut wires, the slack wires and the catenaries to be effected.

6. A rigid'airship as claimed in claim 3, in which connections are madefrom the point of attachment of the catenaries to the circumferentialmesh wiring. V

7. A rigid'airshipas claimed in claim 3, in which the intersectinlongitudinal girders and the transverse frame members are so arrangedthat. their centroids are coincident.

8. A rigid airship as claimed in claim 3 in which the degree ofslackness initially imparted to the slack wires .of each successivepanel is made progressively greater from a minimum at the bottom of theairship to a maximum at the top thereof. v

i 9. A rigid airship as claimed in claim 3 in which an axial restraintis provided at or about the centre of the bulkhead wiring.

10. A rigid airship as claimed in claim 3, in which an axial restraintconstituted by a rigid girder is provided in proximity to the center ofthe bulkhead wiring, thetaut and slack wires being attached thereto.

11. A rigid airship, comprising in combination longitudinal andtransverse rigid members, provided with an axial restraint constitutedby a rigid girder constructed in removable sections, bulkhead wiringattached to said transverse members and to said girder, and meanswhereby the portions of said girder on opposite sides of any one of saidremovable sections (other than the end sections) may be retracted fromsaid sec tion to permit of its removal. 7

CHARLES DENNISTON BURN EY.

BARNES NEVILLE WALLIS.

JOHN EDWIN TEMPLE.

